Work, Energy and Power

26. A person pushes a block horizontally. If the force and displacement are in the same direction, what is the work done on the block?

a) Positive

b) Negative

c) Zero

d) Cannot be determined

27. A machine does 1000 J of work in 10 seconds. What is its power?

a) 100 W

b) 250 W

c) 500 W

d) 1000 W

28. Which of the following is an example of potential energy?

a) A moving car

b) A falling rock

c) A stretched rubber band

d) A compressed spring

29. The work done by a force can be calculated by multiplying the:

a) Force applied and time taken

b) Force applied and distance moved

c) Mass and acceleration

d) Velocity and time taken

30. A 200 kg car is moving at a velocity of 5 m/s. What is its kinetic energy?

a) 250 J

b) 500 J

c) 2500 J

d) 5000 J